It is described as being almost hive like, with a large central hall reaching from the floor to the tip of the mountain. It has a ledge spiralling around the outside with a series of tunnels connecting various other locations.
- Living quaters, which include rooms with beds, cafeteria and shooting range.
- Multiple labratories.
- Detention centres holding prisoners including humans, animals, Number Six, Katarina, Number Nine, Sandor and Sam at various times. All human prisoners were later taken to Dulce base.
- Rooms with rows of computers and mogadorians checking for anything related to the Garde in the news.
- The Manufacturing area of a Green Lava material used for an unknown reason. There was a mote of this surrounding the chests when Sam Goode and Number Four attempt to recover them, John discovers that he could manipulate this as with any fire.
- Animal quarters, holding Piken and Krauls amongst other previously unseen creatures.
Six and Katarina are caught in New York and brought to the mountain base where Katarina is tortured and eventually killed. Six is imprisoned there until she discovers her Invisibility and manages to escape, avenging Katarina's death first. Six notes the location of the base and is later able to direct Four and Sam to the base to retrieve Four's chest.
Nine is betrayed by Maddy who leads the Mogadorians to him, he almost manages to escape but is tazered. He is brought to the mountain base where he occupies himself by keeping fit. Eventually Sandor is also found and brought to the base where he is tortured in front of Nine who breaks out of the forcefield that confines him and kills Sandor out of mercy. Nine stays in the base as a prisoner for around a year and is eventually freed by Four and Sam.
The Fallen Legacies (Mentioned)
Upon showing signs of weakeness following the apparantly failed memory transfer experiment and failing to kill Number Two, Adamus' father Andrakkus threatens to send him to the mountain base to take part in training, something that his wife manages to talk him out of. Adamus notes how labourous this training would be.
Both Sam and Four enter the base using the Xitharis charged with Six's Invisibility, in order to recover his Loric Chest. They are unable to locate the chest until Four suggests that it would be hidden in the most dangerous place of the cave, the animal pen. Here they find the chest, along with another chest and Four battles a large ape creature and causes a large explosion that erupts throughout most of the base in order to escape. In the tunnels they find rows of prison cells, one bursts open and they meet Number Nine who had been imprisoned there for a long time. Nine is reunited with his chest and the group fight the oncoming mogadorians and creatures.
The Rise of Nine (Seen)
After escaping the base, Nine and Four make it a few miles before the truck runs out of gas. They hide in an abandoned house. Once Four has recovered from hitting the force field, Bernie Kosar leads him to a peak where they are able to see the blue light of the force field. Four immediately plans to return but, after using the communicator in Nine's chest, they are soon captured by the FBI.